Method and apparatus for providing a controlled supply of sulphur combustion gases



Feb. 2, 1943.

METHOD AND AP'PARA SUPPLY 0F 3 Sheet INVENTORS JOHN B. (HAH-Z4 s-Sheet 1 ATTORNEYS METHOD, AND` -APPARATUS FOR PROYIDING A CONTROLLED SUPPLY OF SULPHUR GOMBUSTION GASES Filed June 7, 1939 3 Sheets-Sheet 2 -Fell 2, 1943- .J B. CHATLAIN Erm. r 2,310,173

'30 INVENTORS JOHN 5. CHATEL/HN BY GOEDO Q CA IN ATTORNEY 2,310,173 LED Feb- 2, 1943- J. B. CHATELAIN Erm.

METHODv AND APPARATUS FOR PROVIDING A CONTROL SUPPLY -OF SULPHUR COMBUSOTION GAS Filed June CHA TELA/N 3 Sheets-Sheetv 3 Bi.. 602004/ A, CAI/v ATTORNEY Patented Feb. .2, 1.943 I UNlTEDQsTATEs PATENT OFFICE METHOD AND APPARATUS FOR PROVID- ING A coNTRoLLEn SUPPLY oF sULPnUR COMBUSTION GASES John B. Chatelain and Gordon A. Cain, Freeport, Tex., assignors to Freeport Sulphur. Gompany, New York, N. Y., a. corporation of Delaware Application June 7, 1939, Serial No. 277,908 s claims. (c1. zza-avt) This invention relates new and improved apparatuses and methods for providing a controlled .supply of sulphur combustion gases, more parfrom the combustion chamber, and the` amount of combustion supporting gases supplied. The relative importance of each of these variables becomes greater as the quantity of combustion gases required becomes less, the range within which they must be controlled becomes narrower, and the demand for consistency in them becomes higher.

Many sulphur burners and methods of burning sulphur have heretofore been described that will operate satisfactorily if the rate at which sulphur is to be burned is comparatively high and variable amounts of combustion products of high consistency are not demanded. However, the operation of conventional burners at rates wherein sulphur is burned in comparatively small portions within narrow limits, is attended with great diilicuity of control, requiring constant supervision to mainu tain the burning rates within such limits. Fui"n thermore, it is generally recognized that the operation of various conventional types of sul phur burners at very low burning rates is accomplished by the likelihood of cessation of vcombustion and interruption of continuous operation.

Although sulphur dioxide gases and particularly its solutions in water have applications in industrial processes, its use in many of these processes requiring only very small, continuous but variable and accurately controlled amounts of sulphur dioxide has been limited due to the cost of providing compressed, or liquid sulphur dioxide, or cost of supplying the necessary addi tional equipment to control accurately the feeding thereof. The cost of such equipment and the supervision required to, produce sulphur dioxide by burning sulphur at accurately controlled and easily varied rates has heretofore `proven prohibitive. The latter is peculiarly true in operations which require the use of sulphur dioxide under pressure. For instance, according to past practices, it has often proven impractical to use sulphur dioxide in many flocculation, 'reductie bleaching and acid imparting and alkalinity reducing processes because of the cost of the raw materials and equipment necessary.

It is an object of the present invention to provide processes and apparatuses for supplying a controlled supply of sulphur combustion gases at rates which will make the use of said combustion gases commercially feasible in processes heretofore found unproii-table. A further purpose of this invention is to provide a method and an apparatus for burning sulphur at variable rates to produce sulphur dioxide of high consistency in easily controllable quantities.

More particularly the object of this invention is to provide a method and apparatus for burning sulphur continuously at relatively low rates under complete control to produce sulphur dioxide in variable amounts exactly in the quantities desired. In obtaining these objectives, the number of variable factors allee-ting the rate of the burning.

of sulphur, are in accordance with the present invention, reduced to a minimum such that the amount and consistency of the combustion gases produced are easily controlled by regulation of the remaining variable quantities. Constancy is obtained primarily by providing a supply of liquid sulphur in such relation to the combustion chamber and with such connections that the sulphur is caused to flow into the combustion chamber at a point below the surface of the burning sulphur without agitating this surface and in accordance with a control system which is automatically responsive to the level of the sulphur in. the combustion chamber. With the arrangement apparatus hereinafter described, the amount of sulphur combustion gases produced under ordinary circumstances will vary indirect proportion to the amount of combustion support ing gases introduced into the combustion chamber. When the amount of combustion gases to be produced is extremely small and the reneyments more exacting, the quantity and the consistency of the combustion gases can be further modified by controlling the rate of heat loss from the .combustion chamber as will hereinafter be more fully described.

The preferred constrctionand features of our invention will be made apparent by the following detailed descriptions of several illustrative embodiments of the invention when considered in conjunction with the accompanyingrawings.

In the drawings, Fig. 1 is a view in vertical l section of a typical embodiment of the invention.

The apparatus shown in Fig. A2, in vertical section, illustrates a second embodiment provided With means'for maintaining the temperature of the sulphur supply constant and in the molten condition.

The apparatus shown in Fig. 3,.likewise in vertical section, illustrates a third embodiment provided with a cone-shaped' combustion chamber whereby the surface area of the sulphur in such chamber can be altered by varying the depth of the sulphur therein.

In Fig. 1, there is shown a combustion cham-v ber I II having an inlet.II for the combustion supporting gases providedwith a control valve I2, an outlet I3 for theicombustion gases provided with an' auxiliary ejector I4. A sulphur supply source I5 is connected to a liquid sulphur lsupply container' I6 through a valve Il, the

container. I6 being connected to the combustion chamber I0 through a conduit I8 terminating near'the bottom of the chamber or below the level of the sulphur to be .maintained therein and a conduit I9 terminating at a higher point in the chamber or at the level of the sulphur, I

- I 3a containing a control damper 29. The combustion chamber i0 may be enclosed in a jacket 30 for steam or other heating or cooling gases. e In Fig. 3, wherein the same numbers are used, the conduit I8 is connected with a conduit I9a having therein a screw threaded adjustable stern 35 connected to a movable extension conduit 36 for varying the depth of the liquid inthe conical shaped combustion chamber Illa. A scale 3l and pointer 38 are provided in connection with the stem 35 to indicate the height of the liquid in the combustion chamber and its surface area.

In starting the operation of the equipment, the burner or combustion chamber I6 or Illa is filled to a level below the end` ofv conduit I9 or 36 with either solid or molten sulphur by introducing the same through. the hand hole 2|, or from the supply source I5 through the valve I'i, the supply container I6 and the conduit I8. When the sulphur has reached the proper level in the burner I0, the supply container I6 is illled with molten sulphur from the: supply source I5. The sulphur is lighted by means of a match introduced through the handhole 2|.

A draught is created through the burner by forcing air or other gaseous medium through the auxiliary conduit III. When the flame has spread -over theentire area of the sulphur hand hole 2Iy is closed, ,air is supplied through the inlet Il,

v and the air pressure in conduit I4 is cut out-of ',operation. The combustion supporting gases may be supplied through inlet II by an. adjustable blower or any other suitable device. Y When combustion has reached a desirable stage, valve'20 is opened, valve II being kept closed. A part of the liquid sulphur inthe container I6 will then ow through the conduit I8 and enter the burner at a'. point near its bottom, the sulphur, continuing to iiow into the burner as long as air or gas can enter the conduit I9 and pass up the conduit I8 to the container I6, or until the level of the pool of molten sulphur reaches the level of the opening of the conduit I9. l

Automatic operation oi the system is obtained by reason of the fact that a partial vacuum is created in the container I6 and, as the sulphur is burned in the combustion chamber I0 and the level of the sulphur is lowered below the opening of conduit I9, air enters and permits 'sulphu to flow to the burner until the level rises to a point which stops the ingress of air. The level of liquid sulphur in the burner hence will' remain constant or not vary more than a very small fraction of an inch.

-"When the supply of sulphur in the container I6 is near exhaustion the valve 20 is closedand the valve I1 is opened to admit more sulphurv through the valve Il and through the molten sulphur of the supply source I5 into the atmosphere above, thereby allo ng a free flow of the molten sulphur into the container I6. When the container I6 has become filled with sulphur, valve I'I is closed and valve 20 is opened, thereby again putting into operation the automatic feedingand constant control mechanism.

Since the sulphur in the supply chamber I5 and that in the container I6 musi; be melted and maintained in such a condition, some external heating means must be employed. This heat can be supplied by providing a steam jacket, or by windings of suitable electric heating wire or by any other convenient means, such as by causing the hot combustion gases which -leave the burner I0 through the outlet conduit I3a to 'pass through a jacket 25 surrounding the container I 6 and the hopper I5 as illustrated in Fig. 2 of the drawings. Dampers 2l and 29 in conduit 26 and in the outlet I 3a respectively may be used to control the amount of combustion gases which are diverted and caused to pass through the jacket 25. By-

` regulating the position of the dampers 2l and 29,

the temperature in the supply source I5 and the container I6 Iis controlled.

In Fig. 2 the burner I0 is shown surrounded by a jacket 30 which permits an even more finite control of the quality of the combustion gases produced, especially Awhen small portions of sulphur arebeing burned at a slow rate, by controlling the rate of heat loss from the combustion chamber.

The dimensions of the combustion chamber I0 may vary within wide limits depending upon the rate of sulphur burning desired and the rate of further control means enabling the operator'to' vary the surface area of the burning sulphur.

The combustion chamberv mais an invertedcone presenting a different horizontal crossfsectional area at every different level, the level of the sulphur therein being controlled at will by the operator through raising or lowering of the conduit 36. The same results may be obtained by a pyramid or any other similar figure having a variable horizontal cross-sectional area.

The apparatus of each of the embodiments hereinbefore described provides a constant supply of liquid sulphur to the combustion chamber at a distance below the' surface of the burning sulnot only has a constant vdepth in the combustion chamber but also has a, constant area of burning surface. The combustion space above the burning surface is also constant.- Only two variables, namely the rate of heat loss from the combustion chamber and the rate of supply of combustion supporting gases, are left to be controlled. Of

these two remaining variables the amount of heat loss from the surface of the'combustion chamber is of relatively much less importance.

Therefore, a constant supply of combustion supporting gases will provide a constant amount of sulphur combustion gases of satisfactory consistency. Wide variation in the amount of such gases produced may be had by merely varying the amount of combustion supporting gasespsup` to supplyv sulphur dioxide of satisfactory consistency over a range of 40% to 200% of the rated capacity of the sulphur burner, merely by vary-y ing the volume of the combustion supporting `gases.

Only when it is desirable to produce very small -quantities of sulphur combustion gases within very narrow limits and of high consistency is it desirable to control the amount of heat loss from the combustion chamber. vSuch controls are sometimes necessary where the rate of sulphur burning is not more than one pound per hour. Thisloss of heat may be controlled by any suitable means of heat insulation or heat control.

It issometimes desirable, however, to control' the amount of heat radiation when the burner is `being operated at a. rate greatly in excess of its normal capacity. In this instance it is necessary l to increase the rate of heat loss from the combustion chamber which may beV done by using cool blasts of air, by, water jackets, by sprays or by other known methods. I

Through a correlation of the amount of com-- develop in the burning of sulphur and form a scum or a film on the burning surface. This lm becomes. relatively constant after the comf b ustion has progressed for a short period of time, for in the instant apparatus, the surface is not disturbed by the sulphur replenishing operation, the sulphur being slowly fed into the burner at a point below the vburning surface.

An advantage of the apparatus of the invention is that it can be operated under either atmospheric or superatmospheric pressures. Since the sulphur supply container is sealed, the. differentiation between the pressure above the liquid in the supply container and that at the surface of the burning liquid is the same regardless of the pressure conditions existing in the combustion chamber. This advantageous operation would not be possible if the source of supply of the liquid sulphur were exposed to the atmosphere.

For instance, considera burner operated under atmospheric pressure of 14.7 pounds per square inch with the height of the sulphur' in the supply container 4 feet above the level of the sulphur in the combustion chamber. When the sulphur is at this level, the vacuum holding .up the column Y of sulphur is 4 x 0.8 or 3.2 pounds per square inch stance, the applicants have found that justth'" bustion supporting gases and the rate of heat production of sulphur combustion gases may be procured by maintaining thesupply of combustion supporting gases constant and varying the rate of heat loss.

The process and apparatus 0i' the instant invention takes into account the traces of oil which gauge, the pressure of one foot of molten sulphur being figured at 0.8 pound per square inch. Actually a pressure of 14.7-3.2 or 111.5 exists in the space above the level of the surface. If the level of the sulphur in the supply container were to fall to 3 feet above the level of sulphur in the oombustion chamber, the vacuum holding up the column of sulphur is equal to 3 x 0.8 or 2.4 pounds per square inch gauge. This principle will continue to operate unti1 all the sulphur is fed from the sulphur container.

Assuming the same state of facts, except that the operating pressure is 25 pounds per square inch, then the pressure above the column when at the four-foot level will be 25-3.2 or 21.8 pounds per square inch. but the pressure above the liquid in the combustion chambers., is 25 pounds per square inch, and the dierential remains the same as heretofore. Therefore the functioning of the apparatus is independent of the pressure conditions. Naturally thev same principles would operate if the pressure were sub-atmospheric.

Various attachments may be added to increase the efliciency or convenience of operation of the apparatus of .the present invention. For injright amount of sulphur dioxide needed for treating liquid or other materials can be obtained by using a metering device which regulates the supply of combustion supporting gases in direct proportion to the volume of liquid or other material being treated. The metering device is built up on the basis vof experimentation and a plotting of curves showing just the amount of combustion gases needed to supply thedesir'ed sulphur dioxide for the varying amounts of materials being treated.

'Ihe simplicity. ease of control, and the inexpensiveness of the burners and processes of this invention and their adaptability to the productions of small quantities of sulphur dioxide of high consistency makes them useful in many ilelds where prior knownprocesses and appara'- tuses have proven too expensive, too complex, or

even inoperative. Such ilelds of use include, for f instance, supplying sulphur dioxide to boiler water to form alkaline sulphites thereby reducing the alkalinity of the liquid in the boiler and at the same time providing alkaline sulphites for the removal of dissolved oxygen and alkaline sulphates for the proper maintenance of the sulphate-carbonate ratio in the boiler water. Sulphur dioxide produced by our process can likewise be utilized in treatment of municipal water for reducing the pH of such water to the point of optimum occulation'for various coagulants, thereby effecting more eiiicient removal of coloring and suspended matter while employing lower doses of coagulants. The sulphur dioxide can alsol be used in municipal water treatment as an antichlor or as a decolorizer; The use of sulphur dioxide as a decolorizing and bleaching agent in the manufacture of sugar and a. bleaching agent .for certain textiles is likewise made easier. l The ready availability of sulphur dioxide produced.

in accordance with the processes of this invention makes its use, in many instances, preferable to the use of acids such as sulphun'c acid, because its employment involves less danger and the product is much more easily handled, The provision of sulphur dioxide under pressure in easily controlled amounts makes the use of the process advantageous in any instance where the production of sulphites .and/or sulphates is desired.

The example will serve to show the general principles of operation and will show the constancy with which .a burner will operate. e Example 1 ,A burner of the type described having a burning surface of 1.1 'square feet burned an average of 1.78 pounds of sulphur per hour for a period of 77 hours. During this entire period the air supplied the burner remained constant at 7 cubic feet per minute. The maximum burning rate re corded during this period was 1.83 pounds per hour with the minimum being 1.59 pounds per hour. The temperature of the combustion gases leaving the burner varied from a minimum of 375 F. to a maximum of 390 F. The level cony troller maintained a level that varied a maximum of one-sixteenth inch from the average during a one month period of operation.

In another burner it was found that a variation in the supply of air from 10 cubic feet per minute to 40 cubic feet per,minute resulted ina sulphur consumption varying directly with the supply of air and ranging between about 3.1 to 6.15 pounds per hour. The variation in sulphur consumption per unit of time wasas small as in ing equipment which will automatically change the rate at which air is supplied the burner as the volume of the material which is receiving sulphur dioxide treatment varies. Such a method makes it possible to produce sulphur herein but that it extends to all equivalents which one skilled in the art would consider within the general purport of the instant disclosure as limited only by the tenor of the specication and the requirements of the appended claims.

We claim:

1. In an apparatus for providing a controlled supply of sulphur combustion gases, a combustion .chamber having an inlet for combustion supporting gases and an outlet for combustion gases, a closed liquid sulphur supply container positioned at a higher level than that of said combustion chamber, a sulphur supply conduit connected with said supply container and terminating in the combustion chamber, a conduit branching from the said supply conduit and terminating in said combustion chamber at'a level above the terminal of said supply conduit, valve means adapted to stop passage of uids in said -conduits between the sulphur supply container and the combustion chamber when the sulphur supply container is opened to the atmosphere for refilling.

2. In the production of sulphur combustion gases, the method of providing a constant supply of such gases from aburning surface of a liquid body of sulphur in a combustion chamber which comprises, supplying liquid sulphur to the body of burning sulphur at the rate the sulphur is consumed in said chamber by maintaining a column of liquid sulphur contiguous with and at a higher level than that of the body of sulphur in the combustion chamber, said column being retained by differences in gaseous pressure upon the surfaces of the column and the body of liquid, and in response to the loweringr of the level of the liquid sulphur in the comfbustion chamber due to combustion of sulphur, admitting sulphur from said column to restore the level in said chamber by increasingthe gaseous pressure upon the surface of the` liquid in the column.

3. In the production of gases, the method oi' providing a constant supply of such gases from a burning. surface of a liquid body of sulphur in a combustion chamber` which comprises, supplying liquid sulphur to the body of burning sulphur at the rate the sulphur dioxide at' a variable rate, accurately controlled I within narrow limitsinan automatic manner. the only manual operation required being the daily filling of the molten sulphur supply con,-

is consumed in said chamber by maintaining under partial vacuum a column of liquid sulphur contiguous with and at a higher level than that of the body of the sulphur in the combustion chamber and in response to the lowering of the level of sulphur in said combustion chamber as sulphur therein is consumed, introducing gas into the partial `vacuum in a quantitywhich per- 'mits sufficient sulphur to restore the surface level thereof in the combustion chamber.

4. In an apparatus for providing a controlled supply of sulphur combustion gases, a combustion chamber having an inlet for combustion supporting gases and an outlet for combustion gases, a closed supply container positioned for gravitational flow of sulphur into said combustion chamber. a liquid-sulphur supply conduit connected to said supply container and terminating in the combustion chamber, and a second conduit connected to said container terminating in the `combustion chamber at a point above the terminal of said supply conduit, said conduits having valve means for stopping the passage of uids therethrough when the sulphur supply container is opened to .the atmosphere' for redlling.

5. In an apparatus for burning sulphur and controlling the supply of combustion gases, a

combustion chamber having a variable horizontal cross-sectional area and having an inlet for air and an outlet for combustion gases, a closed liquid sulphur supply container positioned for gravitational ow of sulphur into said combus tion chamber,a conduit connected to said container and terminating in said combustion chamber, a second conduit connected to said container and terminating at a point above the rst mentioned conduit and having means for varying the level of its terminal, said' conduits being provided with valve means for discon tinuing the flow of fluids between said supply container and said combustion chamber.

6. In an apparatus for providing a controlled supply of sulphur combustion gases, a combustion chamber having an inlet for combustion supporting gases and an outlet for combustion gases, a. closed liquid sulphur supply container positioned at a vhigher level than that of said combustion chamber, a conduit connected to said supply container and terminating in the combustion chamber at a point below the desired surface level for burning sulphur, a second conduit connected-to said supply container and havingits lower extremity positioned at a level above that of the rst conduit, a supply tank positioned above said supply container connected therewith, said supply container and supply tank being surrounded by a jacket connected with saidv outlet for combustion gases.

JOHN B. CHATELAIN. GORDON A. CAIN.

" Patent No.'2,51o,175 .4

CERTIFICATE oF CORRECTION.

- February 2, 151;.5. JOHN B. CHATELAIN, AL

It is hereby certified thatl errorv appe'rs in the printed specification of the above numbered patent requiring correction as follows: Page 1 frst column, lines 56 and 5 7, for "accomplished'l read -I-accompaniedn; page 11 second. column,` line 20, before "valve'l insert -'pnd; qnd'that the s aid Letters Patent should be read with this correction therein that the same may conform to the recordof the case in the Patent Office.,

signed am sealed this 50th day cruel-ch, A. D. 1915.

Henry Van Arsd'ale, (Seal) l 'Acting Connnissionr of Patents. 

